Synodic monthly rhythms in the Mongolian gerbil Meriones unguiculatus∗∗

This research was supported in part by an N.S.F. Graduate Trainee Fellowship and by an N.I.H. Public Health Service Fellowship, no. 1‐F01‐GM43579–01. It is based upon a portion of a thesis submitted in partial fulfillment of the requirements for the Ph.D. degree in biological sciences at Northwestern University, Evanston, Illinois.

Abstract

A synodic monthly rhythm of spontaneous activity in the Mongolian gerbil, Meriones unguiculatus is reported. Gerbil activity, plotted as deviation from a seasonal daily mean computed for each day of the synodic month for the four seasons separately, generally reaches maxima shortly after new moon and full moon. Minima occur around last quarter and several days before full moon. This pattern persists for the summer, fall and spring cycles, whereas the winter cycle is primarily a mirror image of the former three. Similarity is present in the cycle form and phase relationship (or an inversion of it) among the gerbil, hamster and mealworm. This similarity and also the extraordinary phase‐synchronization of the gerbil cycle from season to season suggests strongly that all organisms were influenced by a subtle factor or factors and that this factor(s) effected the varying degrees of spontaneous activity.

Abstracting keywords:

• Biological rhythms
• Meriones unguiculatus,
• mongolian gerbil

Notes

This research was supported in part by an N.S.F. Graduate Trainee Fellowship and by an N.I.H. Public Health Service Fellowship, no. 1‐F01‐GM43579–01. It is based upon a portion of a thesis submitted in partial fulfillment of the requirements for the Ph.D. degree in biological sciences at Northwestern University, Evanston, Illinois.

Dept of Biology, California State Univ., San Diego, Calif. 92115, U.S.A.